Wall Street's sell-off resumes

NEW YORK (AP) — U.S. stocks are back to falling sharply on Thursday, led by AI superstars now feeling the painful downside of big expectations.The S&P 500 was down 1.8% in afternoon trading, resuming its slide after a mini-recovery from the prior day helped it claw back some of its sharp drop over recent weeks. The Dow Jones Industrial Average was down 512 points, or 1.2%, as of 1:09 p.m. Eastern time, and the Nasdaq composite was 2.4% lower.Semiconductor compa